| Message ID | alpine.DEB.2.21.1904161608570.1685@nanos.tec.linutronix.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [V5,01/32] mm/slab: Remove broken stack trace storage | expand |
On 4/16/19 4:10 PM, Thomas Gleixner wrote: > kstack_end() is broken on interrupt stacks as they are not guaranteed to be > sized THREAD_SIZE and THREAD_SIZE aligned. > > As SLAB seems not to be used much with debugging enabled and might just go > away completely according to: > > https://lkml.kernel.org/r/612f9b99-a75b-6aeb-cf92-7dc5421cd950@suse.cz > > just remove the bogus code instead of trying to fix it. > > Fixes: 98eb235b7feb ("[PATCH] page unmapping debug") - History tree > Signed-off-by: Thomas Gleixner <tglx@linutronix.de> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Pekka Enberg <penberg@kernel.org> > Cc: linux-mm@kvack.org Acked-by: Vlastimil Babka <vbabka@suse.cz> Thanks. > --- > V5: Remove the cruft. > V4: Make it actually work > V2: Made the code simpler to understand (Andy) > --- > mm/slab.c | 22 +++------------------- > 1 file changed, 3 insertions(+), 19 deletions(-) > > --- a/mm/slab.c > +++ b/mm/slab.c > @@ -1470,33 +1470,17 @@ static bool is_debug_pagealloc_cache(str > static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr, > unsigned long caller) > { > - int size = cachep->object_size; > + int size = cachep->object_size / sizeof(unsigned long); > > addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)]; > > - if (size < 5 * sizeof(unsigned long)) > + if (size < 4) > return; > > *addr++ = 0x12345678; > *addr++ = caller; > *addr++ = smp_processor_id(); > - size -= 3 * sizeof(unsigned long); > - { > - unsigned long *sptr = &caller; > - unsigned long svalue; > - > - while (!kstack_end(sptr)) { > - svalue = *sptr++; > - if (kernel_text_address(svalue)) { > - *addr++ = svalue; > - size -= sizeof(unsigned long); > - if (size <= sizeof(unsigned long)) > - break; > - } > - } > - > - } > - *addr++ = 0x87654321; > + *addr = 0x87654321; > } > > static void slab_kernel_map(struct kmem_cache *cachep, void *objp, >
--- a/mm/slab.c +++ b/mm/slab.c @@ -1470,33 +1470,17 @@ static bool is_debug_pagealloc_cache(str static void store_stackinfo(struct kmem_cache *cachep, unsigned long *addr, unsigned long caller) { - int size = cachep->object_size; + int size = cachep->object_size / sizeof(unsigned long); addr = (unsigned long *)&((char *)addr)[obj_offset(cachep)]; - if (size < 5 * sizeof(unsigned long)) + if (size < 4) return; *addr++ = 0x12345678; *addr++ = caller; *addr++ = smp_processor_id(); - size -= 3 * sizeof(unsigned long); - { - unsigned long *sptr = &caller; - unsigned long svalue; - - while (!kstack_end(sptr)) { - svalue = *sptr++; - if (kernel_text_address(svalue)) { - *addr++ = svalue; - size -= sizeof(unsigned long); - if (size <= sizeof(unsigned long)) - break; - } - } - - } - *addr++ = 0x87654321; + *addr = 0x87654321; } static void slab_kernel_map(struct kmem_cache *cachep, void *objp,
kstack_end() is broken on interrupt stacks as they are not guaranteed to be sized THREAD_SIZE and THREAD_SIZE aligned. As SLAB seems not to be used much with debugging enabled and might just go away completely according to: https://lkml.kernel.org/r/612f9b99-a75b-6aeb-cf92-7dc5421cd950@suse.cz just remove the bogus code instead of trying to fix it. Fixes: 98eb235b7feb ("[PATCH] page unmapping debug") - History tree Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: linux-mm@kvack.org --- V5: Remove the cruft. V4: Make it actually work V2: Made the code simpler to understand (Andy) --- mm/slab.c | 22 +++------------------- 1 file changed, 3 insertions(+), 19 deletions(-)